How to use the optimist.argv.port function in optimist

var util = require('util'),
    http = require('http'),
    argv = require('optimist').argv;

var port = argv.p || argv.port || 8000;

http.createServer(function (req, res) {
  console.log(req.method + ' request: ' + req.url);
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.write('hello, i know nodejitsu.');
  res.end();
}).listen(port);

/* server started */
util.puts('> hello world running on port ' + port);

#!/usr/bin/node
/* r2.js irc bot -- author: pancake(nopcode.org) */
/* TODO: use node-daemon and chroot */

var OPT = require ("optimist").argv;
var IRC = require ('irc.js');
var irc;

/* config */
var nick = OPT.nick || "r2bot"
var channel = OPT.channel || "#radare"
var host = OPT.host || "irc.freenode.net"
var port = OPT.port || 6667
var owner = OPT.owner || "pancake";
var file = OPT.file || "/bin/ls"
var limit = OPT.limit || 10;

const msgtimeout = 1000
const Chi = "\x1b[32m"
const Cend = "\x1b[0m"
const print = console.log

function finalize() {
	if (irc) irc.privmsg (channel, "byebye");
	print ("^C :D");
	process.exit (0);
}
if (channel[0] != '#')
	channel = '#'+channel;

#!/usr/bin/env node
// Copyright IBM Corp. 2013,2019. All Rights Reserved.
// Node module: strong-docs
// This file is licensed under the MIT License.
// License text available at https://opensource.org/licenses/MIT

var Docs = require('../lib/docs').Docs;
var argv = require('optimist').argv;
var path = require('path');
var fs = require('fs-extra');
var debug = require('debug')('strong-docs:cli');
var port = argv.port || process.env.PORT || 3000;
var express = require('express');
var configPaths = {};
var configPath = argv.config || argv.c || 'docs.json';
var config;
var outputPath = argv.out || argv.o;

// --html-file
// The file name for generated html
var htmlFile = argv['html-file'] || 'index.html';
var tsConfig = argv.tsconfig;
var tsTarget = argv.tstarget;
var previewMode = argv.preview || argv.p;
var packagePath = argv.package || 'package.json';
var package;
// --skip-public-assets
// Do not copy `public` assets as it can be shared

};
if (typeof argv.render !== 'undefined') {
    settings.type = argv.render;
}

if (typeof argv.to !== 'undefined') {
    settings.exportPath = __dirname+argv.to;
}

if (typeof argv.upload !== 'undefined') {
    settings.uploadPath = __dirname+argv.upload;
}


if (typeof argv.port !== 'undefined') {
    settings.port = argv.port;
}




var app = express();
app.use(bodyParser.json());
app.use(express.static('html'));
app.set('view engine', 'ejs');
app.set('views', './views')

/* Multer upload diskstorage */
var storage = multer.diskStorage({ //multers disk storage settings
    destination: function(req, file, cb) {
        cb(null, settings.uploadPath)
    },

uploadPath: __dirname + '/uploads'
};
if (typeof argv.render !== 'undefined') {
    settings.type = argv.render;
}

if (typeof argv.to !== 'undefined') {
    settings.exportPath = __dirname+argv.to;
}

if (typeof argv.upload !== 'undefined') {
    settings.uploadPath = __dirname+argv.upload;
}


if (typeof argv.port !== 'undefined') {
    settings.port = argv.port;
}




var app = express();
app.use(bodyParser.json());
app.use(express.static('html'));
app.set('view engine', 'ejs');
app.set('views', './views')

/* Multer upload diskstorage */
var storage = multer.diskStorage({ //multers disk storage settings
    destination: function(req, file, cb) {
        cb(null, settings.uploadPath)

opts.host = opts.host || 'localhost'
    opts.protocol = opts.protocol || 'http'
    
    var protocol = require(opts.protocol)
        
    var server = protocol.createServer(function (instream, outstream) {  
      var streams = setup(args)
      streams.unshift(es.split())
      streams.unshift(instream)
      streams.push(outstream || instream)
      es.pipe.apply(null, streams)
    })
    
    server.listen(opts.port, opts.host)

    console.error(process.argv[1] +' is listening for "' + opts.protocol + '" on ' + opts.host + ':' + opts.port)  
  }
}

var argv = require('optimist').argv;
var path = require('path');

module.exports = {
  server: {
    distFolder: argv.root || '../dist',
    listenPort: argv.port || 1337,
    dataFolder: argv.data || 'data',
    delay: 500
  }
};

var express = require('express'),
  app = express(),
  http = require("http"),
  server = http.createServer(app),
  bodyParser = require('body-parser'),
  multer  = require('multer'),
  zero = require('./system/core/zero'),
  colors = require('colors'),
  argv = require('optimist').argv,
  port = argv.port || 3000,
  path = require('path'),
  compress = require('compression');

app.use(compress());
app.use(bodyParser.urlencoded({ extended: false }))
app.use(bodyParser.json())
app.use(multer({ dest: './uploads/'}))
app.use( '/uploads', express.static( path.join(__dirname,'./uploads')) )


app.engine('jade', require('jade').__express);
app.engine('html', require('ejs').renderFile);
app.engine('ejs', require('ejs').renderFile);

app.set('views', __dirname )

return;
  }
  if (!args[0]) return process.stderr.write('\n');
  var msg = '\x1b[34mServer:\x1b[m \x1b[31m'
    + util.format.apply(util.format, args)
    + '\x1b[m';
  return process.stderr.write(msg + '\n');
}

/**
 * Start Server
 */

server.on('request', app);
server.app = app;
server.port = +argv.p || +argv.port || 8080;

if (argv.s) {
  server.listen(server.port);
  return;
}

if (!module.parent || path.basename(module.parent.filename) === 'index.js') {
  server.listen(server.port, function(addr) {
    if (!isNode) return;
    var customer = require('./customer');
    customer.sendPayment(function(err) {
      if (err) return error(err.message);
      customer.print('Payment sent successfully.');
    });
  });
} else {